|
Retract (group Theory)
Retraction or retract(ed) may refer to: Academia * Retraction in academic publishing, withdrawals of previously published academic journal articles Mathematics * Retraction (category theory) * Retract (group theory) * Retraction (topology) Human physiology * Retracted (phonetics), a sound pronounced to the back of the vocal tract, in linguistics * Retracted tongue root, a position of the tongue during the pronunciation of a vowel, in phonetics * Sternal retraction, a symptom of respiratory distress in humans * Retraction (kinesiology) Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ..., an anatomical term of motion See also * Retractor (other) {{Disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retraction In Academic Publishing
In academic publishing, a retraction is the action by which a published paper in an academic journal is removed from the journal. Procedure A retraction may be initiated by the editors of a journal, or by the author(s) of the papers (or their institution). Retractions are typically accompanied by a retraction notice written by the editors or authors explaining the reason for the retraction. Such notices may also include a note from the authors with apologies for the previous error and/or expressions of gratitude to persons who disclosed the error to the author. A lesser withdrawal of content than a full retraction may be labelled a correction. There have been numerous examples of retracted scientific publications. Retraction Watch provides updates on new retractions, and discusses general issues in relation to retractions. History A 2011 paper in the ''Journal of Medical Ethics'' attempted to quantify retraction rates in PubMed over time to determine if the rate was increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retraction (category Theory)
In category theory, a branch of mathematics, a section is a right inverse of some morphism. Dually, a retraction is a left inverse of some morphism. In other words, if f: X\to Y and g: Y\to X are morphisms whose composition f \circ g: Y\to Y is the identity morphism on Y, then g is a section of f, and f is a retraction of g. Every section is a monomorphism (every morphism with a left inverse is left-cancellative), and every retraction is an epimorphism (every morphism with a right inverse is right-cancellative). In algebra, sections are also called split monomorphisms and retractions are also called split epimorphisms. In an abelian category, if f: X\to Y is a split epimorphism with split monomorphism g: Y\to X, then X is isomorphic to the direct sum of Y and the kernel of f. The synonym coretraction for section is sometimes seen in the literature, although rarely in recent work. Properties * A section that is also an epimorphism is an isomorphism. Dually a retraction that is al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retract (group Theory)
Retraction or retract(ed) may refer to: Academia * Retraction in academic publishing, withdrawals of previously published academic journal articles Mathematics * Retraction (category theory) * Retract (group theory) * Retraction (topology) Human physiology * Retracted (phonetics), a sound pronounced to the back of the vocal tract, in linguistics * Retracted tongue root, a position of the tongue during the pronunciation of a vowel, in phonetics * Sternal retraction, a symptom of respiratory distress in humans * Retraction (kinesiology) Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ..., an anatomical term of motion See also * Retractor (other) {{Disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retraction (topology)
In topology, a branch of mathematics, a retraction is a continuous mapping from a topological space into a subspace that preserves the position of all points in that subspace. The subspace is then called a retract of the original space. A deformation retraction is a mapping that captures the idea of ''continuously shrinking'' a space into a subspace. An absolute neighborhood retract (ANR) is a particularly well-behaved type of topological space. For example, every topological manifold is an ANR. Every ANR has the homotopy type of a very simple topological space, a CW complex. Definitions Retract Let ''X'' be a topological space and ''A'' a subspace of ''X''. Then a continuous map :r\colon X \to A is a retraction if the restriction of ''r'' to ''A'' is the identity map on ''A''; that is, r(a) = a for all ''a'' in ''A''. Equivalently, denoting by :\iota\colon A \hookrightarrow X the inclusion, a retraction is a continuous map ''r'' such that :r \circ \iota = \operatorname_A, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retracted (phonetics)
In phonetics and phonology, relative articulation is description of the manner and place of articulation of a speech sound relative to some reference point. Typically, the comparison is made with a default, unmarked articulation of the same phoneme in a neutral sound environment. For example, the English velar consonant is ''fronted'' before the vowel (as in ''keep'') compared to articulation of before other vowels (as in ''cool''). This fronting is called palatalization. The relative position of a sound may be described as ''advanced'' (''fronted''), ''retracted'' (''backed''), ''raised'', ''lowered'', ''centralized'', or ''mid-centralized''. The latter two terms are only used with vowels, and are marked in the International Phonetic Alphabet with diacritics over the vowel letter. The others are used with both consonants and vowels, and are marked with iconic diacritics under the letter. Another dimension of relative articulation that has IPA diacritics is the degree of ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retracted Tongue Root
In phonetics, advanced tongue root (ATR) and retracted tongue root (RTR) are contrasting states of the root of the tongue during the pronunciation of vowels in some languages, especially in Western and Eastern Africa, but also in Kazakh and Mongolian. ATR vs RTR was once suggested to be the basis for the distinction between tense and lax vowels in European languages such as German, but that no longer seems tenable. Advanced tongue root Advanced tongue root, abbreviated ATR or +ATR, also called expanded, involves the expansion of the pharyngeal cavity by moving the base of the tongue forward and often lowering the larynx during the pronunciation of a vowel. The lowering of the larynx sometimes adds a breathy quality to the vowel. Voiced stops such as can often involve non-contrastive tongue root advancement whose results can be seen occasionally in sound changes relating stop voicing and vowel frontness such as voicing stop consonants before front vowels in the Oghuz Turkic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sternal Retraction
Labored respiration or labored breathing is an abnormal respiration characterized by evidence of increased effort to breathe, including the use of accessory muscles of respiration, stridor, grunting, or nasal flaring. Classification Labored breathing is distinguished from shortness of breath or ''dyspnea'', which is the sensation of respiratory distress rather than a physical presentation. Still, many simply define dyspnea as ''difficulty in breathing'' without further specification, which may confuse it with e.g. labored breathing or tachypnea (rapid breathing). Labored breathing has occasionally been included in the definition of dyspnea as well. However, in the standard definition, these related signs may be present at the same time, but do not necessarily have to be. For instance, in respiratory arrest by a primary failure in respiratory muscles the patient, if conscious, may experience dyspnea, yet without having any labored breathing or tachypnea. The other way around, labored ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retraction (kinesiology)
Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative to the anatomical position of the body parts involved. Anatomists and others use a unified set of terms to describe most of the movements, although other, more specialized terms are necessary for describing unique movements such as those of the hands, feet, and eyes. In general, motion is classified according to the anatomical plane it occurs in. ''Flexion'' and ''extension'' are examples of ''angular'' motions, in which two axes of a joint are brought closer together or moved further apart. ''Rotational'' motion may occur at other joints, for example the shoulder, and are described as ''internal'' or ''external''. Other terms, such as ''elevation'' and ''depression'', describe movement above or below the horizontal plane. Many anatomica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
